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PRACTICAL ORGANIC CHEMISTRY

hydrin. Yield of dichlorhydrin about 120 grams. Epichlor-
hydrin is obtained by the action of aqueous potash solution
upon the dichlorhydrin. A solution of 100 grams of caustic
potash in 200 c.c. of water is well cooled and poured slowly, with
constant stirring, into the dichlorhydrin. Rise of temperature
must be carefully avoided. The epichlorhydrin is separated
from the product by adding ether, which dissolves out the
epichlorhydrin. The upper layer is separated, shaken up
with a little water, and again separated. It is then dehydrated
over calcium chloride and decanted into a round flask. The
ether is first removed on the water-bath. The residue is then
fractionally distilled. This is effected by attaching a fractionat-
ing column to the flask (see p. 137). The portion boiling
at 115  125 is epichlorhydrin, and is collected separately. The
portion boiling above this temperature consists mainly or
acetodichlorhydrin. Yield 25  30 grams.

CH2OH.CI-IOII.CHoOH + HC1 = CH2C1.CHOH.CH2OH + H20.

a-Monochlorhydrin.

CH2CLCHOH.CH2OH + HC1 = CH2C1.CHOH.CH2C1 + H20.

aa-Dichlorhydrin.

CH2Cl.CHOH.CH2Ci + KOH = CHCKLCHoCl + KC1 + H20.

Epichlorhydrin.
Properties.  Mobile liquid, with an ethereal smell ; b. p.
117; sp. gr. 1-203 at o.
Reaction.  Warm a little of the epichlorhydrin with caustic
potash solution. It dissolves, forming glycerol. See Appendix^
p. 260.
CH(OH).COOH
Malic Acid,   |
CH2.COOH
Malic acid is prepared from the juice of the mountain ash
berries by precipitation as the calcium salt.
Properties.  It is soluble in water and alcohol, but not in
ether. On heating, it loses water and is converted into fumaric
and maleic acids (see p. 125). On oxidation it gives malonic acid
and on redaction succinic acid.
Reactions.  r. Make a strong neutral solution, add calcium
chloride solution and boil. The calcium salt is precipitated.